RCD Tripping, Nothing in Sockets, no load... what now?

[Tidy]

Hi Everybody,

We just moved into a detached house in last friday, only to find that the RCD keeps tripping for no reason :S I have had an electrician out who checked the RCD and said the box is fine.. and must be the sockets.

We unplugged every item in the house and tried to turn the socket switch back on (on the CU)... it trips the RCD, after 4 or 5 attempts it holds and we have power. (lights etc are not affected).

If we press the test button the RCD main switch does as it should.... and if we turn the socket switch OFF the main RCD will switch on immediately and hold. If we start to plug items back into the sockets sometimes it trips... sometimes it does not... there is no pattern.

I have pulled all the sockets away from the wall to make sure there are no trapped wires and for any interference with the back plates.. all ok, and still trips for no real reason.

The electrician (as above) has tested the CU with some little plugin things and said its fine and working as it should.

The worst time is the morning (between 8 - 10am), there are no washing machines on, no dryers, the combi boiler is off.. so essentially no load at all.

Other notes of interest is the previous owner who i have contacted (because of mail he needs to pick up) asked about the electrics... his words were

"its the shower, if i wanted to use the shower i had to make sure the washing machine, dryer and microwave was off). I had all the sockets tested and my electrican could not find anything wrong with the wiring.

Surely that would affect the shower switch... and not the sockets switch (the shower is not on the sockets - tested that lol).


I am sorry to pick everybodies brains, but i will go through when it has tripped and see if somebody is blatantly obvious?

1) Plug in extension cable with nothing in... Sockets RCD flicked as well as main RCD
2) Plug in hoover into kitchen socket.... main RCD off
3) Walking across the landing towards the shower... main RCD switch off
4) Jumping on the landing floorboards...no change (in case of rogue nail in floor boards lol)
5) Turning TV sockets on (which has an xbox, DVD player, 50" plasma, Wii), sockets rcd off, main switch off
6) 2 minutes into a shower, sockets off, shower off, main rcd off

This morning when i was just about to have a shower and had to reset the main switch, when i managed to finally get all switched to stick there was a buzzing noise coming from the CU - but it only happened when the shower was turned on (electric shower).

I am at a real loss at what to try next, with everything seeming to be checking out i seem to working (web designer) out of fear that my PC will shut down at any time with no warnings etc...

I am no expert but after many nights browsing the web and trying to diagnose the issue, would it be possible to think that it might be an earth problem for the house?

Thank you all again

 

[Edd]

would love to know the original tripping times of the old RCD as the only time ive found them to give this type of pain in the butt tripping is when they trip at less than 10ms at x1. dont suppose you know?

 

[bigbaddave]

And the fault was??????

Its like doing a jigsaw and the last piece being missing,

 

[Tidy]

Hi Bigbaddave, on page 4 i said he fitted a new RCD switch, since then touch wood no more faults.

 

[CACJL]

Neutral earth short as well as a crossed neutral in the consumer unit, if there is a excessive total length of cable on the RDC, the capacitance currant cause it to trip, say if the capacitance from live to earth approaches say 300nF (300 nano farads).

 

[hightower]

......

 

[alectrician 1]

Cold possibly be a loose connection or loose breaker on the shower circuit, are there any sigas of burning or is the connection hot to touch, with theach power turned off of course

 

[ipf]

Smells like it's been locked away in the attic a while......

 

[Tidy]

Wow, ok this thread was raised and keep receiving email notifications of new replies lol

The issue was fixed by replacing the RCD fuse thing in the fuse box... ever since... no issues at all - so it seemed like it was a little toooo sensitive.

Lay this poor thread to rest, I appreciate all of your replies

 

[Darkwood]

Wow, ok this thread was raised and keep receiving email notifications of new replies lol

The issue was fixed by replacing the RCD fuse thing in the fuse box... ever since... no issues at all - so it seemed like it was a little toooo sensitive.

Lay this poor thread to rest, I appreciate all of your replies

I'll close the thread, its been a while and request acknowledged